CN108294754A - Magnetic resonance multi-parameter quantitative imaging method and device - Google Patents
Magnetic resonance multi-parameter quantitative imaging method and device Download PDFInfo
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Abstract
The embodiment of the present application provides a kind of magnetic resonance multi-parameter quantitative imaging method, and this method is combined using the echo-signal of at least two echo time of same flip angle of acquisition, can be got two-by-twoQuantitative figure, the echo-signal using at least two flip angles same echo time of acquisition combine, can obtain T1 and quantitatively scheme two-by-two.It is gettingAfter quantitative figure and T1 quantify figure, can according at least two echo-signals of acquisition and this getQuantitative figure and T1 quantitatively scheme, and obtain and eliminateEffect and T1 effect water fat separation figure.Utilize the eliminationAccurately Fat quantification may be implemented in effect and T1 effect water fat separation figures.In addition, the embodiment of the present application also provides a kind of magnetic resonance multi-parameter quantitative imaging devices.
Description
Technical field
This application involves Medical Imaging Technology field more particularly to a kind of magnetic resonance multi-parameter quantitative imaging methods and dress
It sets.
Background technology
Magnetic resonance imaging (Magnetic Resonance Imaging, MRI) basic principle is：Proton in tissue
(hydrogen atom) there is spin motion to generate magnetic moment.Under the effect of strong homogeneous main magnetic field, the spin Hydrogen Proton of this No- L aw Order is certainly
Gyromagnet square can be arranged along main field direction, form macroscopic moment.Radio-frequency pulse excitation under, macroscopic magnetization vector will be turned to
The vertical direction of main field, can be received in precession rotary course by radio-frequency receiving system, to generate electromagnetic induction signal,
It rebuilds to form various magnetic resonance image by corresponding data.
Fat signal plays abnormal important role in magnetic resonance imaging.Fat is due to its low T1 value, often in routine
Signal is eager to excel than other signals tissue in scanning.Therefore the picture of fat signal often inhibits the sight of the tissue of other signals
It examines.Although fat is in most cases the contrast for inhibiting tissue, diagnosis is influenced, with living condition
Improve, it is fat also to become great and prevalent disease one kind.If the fat constituent in human body critical tissue can accurately be measured,
It is highly useful for many diseases of early prevention.Fat quantification technology is exactly to be proposed under the premise of the background.
The basic conception of Fat quantification is to use fat signal F divided by the sum of water signal W and fat signal F, obtains fat ratio
Example Fat_Quant, formula are as follows：
Ratio fatty in signal can be accurately calculated from formula (1), this has great significance to clinical diagnosis, than
Such as fatty liver seriously arrives any degree.
As can be seen that the Accurate Determining of Fat quantification is necessarily dependent upon water fat separation skill from the calculation formula of Fat quantification
Art.
Although existing water fat isolation technics can realize that water fat detaches well, in water fat separation process not
ConsiderEffect and T1 effects, or only account forEffect does not account for T1 effects.AndThe influence of effect and T1 effects is led
Cause Fat quantification that can change with the variation of echo time (the echo time, TE).Therefore, if expecting Fat quantification
Accurate result, then need in water fat separation process, by the fat signal acquired and water signalEffect is removed, while right
It also needs to eliminate T1 effects in gtadient echo (gradient echo, GRE) sequence short TR.Therefore, by existing water fat point
The water phase decomposed from technology and the Fat quantification result that fat is mutually calculated are inaccurate, and it is fixed cannot to provide accurately fat
Measure information.
In addition, existing water fat isolation technics cannot be provided with diagnostic valueImage and T1 images.
Invention content
In view of this, this application provides a kind of magnetic resonance multi-parameter quantitative imaging method and devices, to utilize multi-parameter
Information, at the same obtain water fat separate picture,Quantitative figure and T1 quantitatively scheme, and water fat separate picture can be eliminatedEffect and
T1 effects, so as to provide accurately Fat quantification information.
In order to solve the above-mentioned technical problem, the application uses following technical solution：
A kind of magnetic resonance multi-parameter quantitative imaging method, including：
The echo-signal of the more echo gradient sequences of multi collect, the flip angle acquired every time is different, acquires every time multiple times
The echo-signal of wave time, and different acquisition process acquisition multiple echo times correspond to respectively it is identical；
The echo-signal of at least two echo times of the same flip angle of acquisition is combined two-by-two, is obtainedQuantitative figure；
The echo-signal of the same echo time of at least two flip angles of acquisition is combined two-by-two, T1 is obtained and quantitatively schemes；
According at least two echo-signals of acquisition and getQuantitative figure and T1 quantitatively scheme, and obtain the separation of water fat
Figure.
Optionally, the echo-signal of at least two echo times of the same flip angle by acquisition is combined two-by-two, is obtained
It takesQuantitative figure, specifically includes：
The echo-signal of two echo times of the same flip angle of acquisition is combined two-by-two, constitutes one group of combined signal
Group；
By the natural logrithm of two echo-signal ratios in combined signal group echo corresponding with two echo-signal
The difference of time is divided by, and obtained result isQuantitative figure.
Optionally, the echo-signal of at least two echo times of the same flip angle by acquisition is combined two-by-two, is obtained
It takesQuantitative figure, specifically includes：
The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, constitutes multigroup signal connection
It is combined；
It is respectively that the natural logrithm of two echo-signal ratios in every group of combined signal group is corresponding with two echo-signal
The difference of echo time is divided by, and obtained result is each transitionQuantitative figure；
Each transition to being calculatedQuantitative figure sums up averagely, and obtained average result is finalIt is quantitative
Figure.
Optionally, the echo-signal of at least two echo times of the same flip angle by acquisition is combined two-by-two, is obtained
It takesQuantitative figure, specifically includes：
The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, constitutes multigroup signal connection
It is combined；
By in every group of combined signal group two echo-signals and the two echo-signals corresponding echo time substitute into respectively
It arrivesCalculation formula in, solved by least square methodQuantitative figure；
Wherein,Calculation formula it is as follows：
Wherein, SmjFor the echo-signal of the jth echo time of the n-th flip angle；
SmiFor the echo-signal of the i-th echo time of the n-th flip angle；
TEiFor SmiEcho time；
TEjFor SmjEcho time；
Wherein, i, j, m are positive integer.
Optionally, the echo-signal of the same echo time of at least two flip angles by acquisition is combined two-by-two, is obtained
It takes T1 quantitatively to scheme, specifically includes：
The echo-signal of the same echo time of two flip angles of acquisition is combined two-by-two, constitutes one group of combined signal
Group；
According to the difference of the ratio of the sine value of the corresponding flip angle of two echo-signals in the combined signal group
And two the corresponding flip angle of echo-signal tangent value ratio difference functional relation, obtain T1 quantitatively scheme.
Optionally, the echo-signal of the same echo time of at least two flip angles by acquisition is combined two-by-two, is obtained
It takes T1 quantitatively to scheme, specifically includes：
All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, constitute multigroup signal connection
It is combined；
Respectively according to the ratio of the sine value of the corresponding flip angle of two echo-signals in every group of combined signal group
The functional relation of the difference of the ratio of the tangent value of difference and the corresponding flip angle of two echo-signals, obtains each transition
T1 quantitatively schemes；
Figure is quantified to each transition T1 being calculated to sum up averagely, obtained average result is quantitative for final T1
Figure.
Optionally, the echo-signal of the same echo time of at least two flip angles by acquisition is combined two-by-two, is obtained
It takes T1 quantitatively to scheme, specifically includes：
All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, constitute multigroup signal connection
It is combined；
By in every group of combined signal group two echo-signals and the corresponding flip angle of two echo-signals be updated to respectively
In the calculation formula of T1, T1 is solved by least square method and is quantitatively schemed；
Wherein, the calculation formula of T1 is as follows：
Wherein, SqmFor the echo-signal of the m echo times of q flip angles；
SkmFor the echo-signal of the m echo times of kth flip angle；
θqFor q flip angles；
θkFor kth flip angle；
TR is the repetition time；
Wherein, q, m, k are positive integer.
Optionally, it at least two echo-signals according to acquisition and getsQuantitative figure and T1 quantitatively scheme,
Water fat separation figure is obtained, is specifically included：
By collected all echo-signals and getQuantitative figure and T1 quantitatively scheme to be updated to water fat point respectively
Proton density figure from the proton density figure and fat in model, solving water by least square method, to obtain water fat point
From figure；
Wherein, the water fat disjunctive model is to considerThe water fat disjunctive model of effect and T1 effects.
Optionally, the water fat disjunctive model is specific as follows：
Wherein, θ is flip angle,
WPDAnd FPDThe respectively proton density figure of water and fat；
TR is the repetition time；
T1WAnd T1FThe respectively T1 times of water and fat；
WithRespectively water and fatThe inverse of time；
T is the echo time；
Δ f is the difference on the frequency of water signal and fat signal；
Φ is the shared phase of water signal and fat signal.
Optionally, it at least two echo-signals according to acquisition and getsQuantitative figure and T1 quantitatively scheme,
After obtaining water fat separation figure, further include：
Fat quantification information is calculated according to the water fat separation figure got.
A kind of magnetic resonance multi-parameter quantitative imaging device, including：
Collecting unit is used for the echo-signal of the more echo gradient sequences of multi collect, and the flip angle acquired every time is different, often
The echo-signal of secondary acquisition multiple echo times, and multiple echo times of different acquisition process acquisition correspond to respectively it is identical；
Quantitative figure acquiring unit, the echo-signal two of at least two echo times of the same flip angle for that will acquire
Two joints, obtainQuantitative figure；
T1 quantifies figure acquiring unit, the echo-signal two of the same echo time of at least two flip angles for that will acquire
Two joints obtain T1 and quantitatively scheme；
Water fat detaches figure acquiring unit, for according at least two echo-signals of acquisition and gettingQuantitative figure
Quantitatively scheme with T1, obtains water fat separation figure.
Optionally, describedQuantitative figure acquiring unit specifically includes：
First joint subelement, for joining the echo-signal of two echo times of the same flip angle of acquisition two-by-two
It closes, constitutes one group of combined signal group；
First computation subunit, for by the natural logrithm of two echo-signal ratios in the combined signal group and this two
The difference of echo-signal corresponding echo time is divided by, and obtained result isQuantitative figure.
Optionally, the T1 quantifies figure acquiring unit and specifically includes：
Second joint subelement, for joining the echo-signal of the same echo time of two flip angles of acquisition two-by-two
It closes, constitutes one group of combined signal group；
Second computation subunit, for according to the corresponding flip angle of two echo-signals in the combined signal group
The function of the difference of the ratio of the tangent value of the difference of the ratio of sine value and the corresponding flip angle of two echo-signals closes
System obtains T1 and quantitatively schemes.
Optionally, the water fat separation figure acquiring unit specifically includes：
By collected all echo-signals and getQuantitative figure and T1 quantitatively scheme to be updated to water fat point respectively
Proton density figure from the proton density figure and fat in model, solving water by least square method, to obtain water fat point
From figure；
Wherein, the water fat disjunctive model is to considerThe water fat disjunctive model of effect and T1 effects.
Compared to the prior art, the application has the advantages that：
Based on above technical scheme it is found that magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application, utilizes
The echo-signal of at least two echo time of same flip angle of acquisition is combined two-by-two, can be gotQuantitative figure, using adopting
The echo-signal of at least two flip angles same echo time of collection is combined two-by-two, can be obtained T1 and quantitatively be schemed.It is getting
After quantitative figure and T1 quantify figure, can according at least two echo-signals of acquisition and this getQuantitative figure and T1 are fixed
Spirogram is obtained and is eliminatedEffect and T1 effect water fat separation figure.Utilize the eliminationEffect and T1 effect water fat separation figure can be with
Realize accurately Fat quantification.
Description of the drawings
Fig. 1 is more echo gradient sequence diagrams；
Fig. 2 shows the water signal peaks and fat signal peak schematic diagram of the separation of water fat.
Fig. 3 shows water fat with reverse phase schematic diagram；
Fig. 4 is the realization block schematic illustration of magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application；
Fig. 5 is the magnetic resonance multi-parameter quantitative imaging method flow diagram applied for embodiment and provided；
Fig. 6 A to Fig. 6 D are obtained by magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application respectively
T1 quantitatively schemes,Quantitative figure, water signal figure and fat signal figure；
Fig. 7 is the control device for the magnetic resonance multi-parameter quantitative imaging method for executing embodiment provided by the embodiments of the present application
Schematic diagram；
Fig. 8 is magnetic resonance multi-parameter quantitative imaging apparatus structure schematic diagram provided by the embodiments of the present application.
Specific implementation mode
In order to which the specific implementation mode of the application is expressly understood, used when the application specific implementation mode is described below
Technical term do a brief description.
It is T1 relaxation times (also referred to as longitudinal magnetization arrow that the T1 times, which are when the magnetization vector of the longitudinal axis increases to 63% by 0,
Amount).T1, which quantitatively schemes (T1mapping), can describe the variation in 1 relaxation time of tissue T.
The T2 relaxation times are that transverse magnetization vector intensity is decayed to the time needed for 37% by maximum value.
Time be transverse magnetisation decay when due to the factors such as Magnetic field inhomogeneity degree cause faster dephasing back magnetization vector it is strong
Degree decays to the time needed for 37% by maximum value, tissueLess than the T2 relaxation times of tissue.
ForInverse, can also useTo weigh the decaying of transverse magnetization vector intensity.Quantitatively scheme (
Mapping) cause the factor of magnetic susceptibility variation very sensitive tissue iron content element variation etc..
Gtadient echo (GRE, gradient echo) is exactly the echo letter generated by the overturning in relation to gradient field direction
Number.Gtadient echo is called an echo (filed echo), and both its main distinction with spin echo, which is, generates swashing for echo
Encourage mode difference.GRE sequences are always started with a RF pulse less than 90 °.
In GRE sequences, RF excitation pulses one terminate, and just apply one on readout gradient direction and first bear rear positive gradient
.The direction change of gradient pulse is traditionally known as gradient flip.Therefore, proton group successively meet again by experience dephasing-phase
Process, to generate echo-signal.
Repetition time (the repetition time, abbreviation TR) refers to pulse train and executes a required time,
It is to occur the time undergone occur to the same pulse of next cycle from a RF driving pulse.As unit of millisecond.TR is determined
Time between one RF pulse and next RF pulses.TR is the determinant and picture contrast of sweep speed
The main controlling elements of (T1, T2 and proton density contrast).
It is required that echo time (the echo time, abbreviation TE) refers to the generation from first RF pulse to echo-signal
Time.In more echo sequences, the time that RF pulses occur to first echo-signal is known as TE1, until second echo-signal
Time be known as TE2.And so on.The contrast that TE with TR co-determination figures are compared.Can also so it understand, in a TR
It is provided with multiple TE.Each TE corresponds to different echo-signals.
In order to each concept in more echo gradient sequences is expressly understood, please refer to Fig.1 shown in more echo gradient sequences
List intention.In sequence shown in Fig. 1, example goes out two pulse periods, i.e. two repetition times TR1 and TR2.Each heavy
In the multiple time, it is provided with 4 echo acquirement windows, each echo acquirement window corresponding echo time is respectively TE1、TE2、TE3With
TE4。
Before the specific implementation of detailed description the application, water fat isolation technics is described first.
Currently, most basic water fat isolation technics is DIXON water fat isolation technics.The DIXON water fat isolation technics is based on
Following facts：In magnetic resonance imaging, for many regions, both include water peak W and also include fat peak F, the frequency of both
Difference is 3.5ppm, and 220Hz. is had been generally acknowledged that at 1.5T, and Fig. 2 shows two peaks that water fat detaches.
Based on this, because there are such a difference on the frequency between water fat, DIXON water fat isolation technics is different by being arranged
Echo time, make water and fat phase on the contrary and identical, namely what is often called water fat is the same as mutually and reverse phase.Fig. 3 shows water fat with anti-
Phase schematic diagram.Following formula can be obtained from Fig. 3：
W and F can be obtained according in above-mentioned formula (2)：
From the above-mentioned simple derivation of equation can be quickly water and fat are separated, but under actual conditions, not due to field
It is absolute uniform, phase error exists everywhere, obtains water signal in this way and fat signal is imperfect, therefore produce on this basis
The new method of many water fat separation is given birth to.For example, two-point method, line-of-sight course, multipoint method etc..
Currently used for the water fat isolation technics of Fat quantification, there are two main classes：It is most common a kind of typically using multiple spot
Method, while 6-7 echo is acquired, because the echo number of acquisition is more than enough, the unknown number number of equation is just more, in signal modelTake into account, then application ID EAL (Iterative Dixon Water-fat sepration with Echo
Asymmetry and Least squares estimation) method, the i.e. least square method of iteration be by water signal and fat
Signal separates, and simultaneously willEffect is also eliminated, and the fat signal and water signal obtained in this way directly applies to Fat quantification.
Another kind of method is considered in the model of two-point methodEffect, but since the phase of water fat itself is distributed respectively
In the imaginary part and real part of fat signal, then by the transformation of equation, and complicated calculating, it is eliminatedRear water phase and
Fatty phase, is then applied to Fat quantification.
Above-mentioned two classes water fat separation method only consideredEffect, for the long fast spin echo of TR
((turbo spin echo, TSE) sequence is applicable in, but also has T1 effects not account for the short GRE sequences of TR, in this way,
For the short GRE sequences of TR, the Fat quantification information obtained by existing water fat separation method is inaccurate.And they can not
It providesImage and T1 images, these images itself have diagnostic value.
In addition, the existing water fat isolation technics for Fat quantification is all the IDEAL methods for acquiring more echoes, when echo
Between it is long, be not applied for abdomen and need to hold one's breath, the stringent sequence for controlling sweep time.
In addition, the existing water fat isolation technics for Fat quantification can not provide the R2* with diagnostic value
Image and T1 images.
In order to solve drawbacks described above existing for the existing water fat separation method for Fat quantification, the embodiment of the present application carries
A kind of magnetic resonance multi-parameter quantitative imaging method is supplied.This method is believed by the echo of the more echo gradient echo sequences of multi collect
Number, the flip angle that acquires every time is different, and the echo time of multiple echo-signals of homogeneous acquisition correspond to it is identical.In conjunction with figure
The realization block schematic illustration of magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application shown in 4 is it is found that the application
Embodiment is combined two-by-two using the echo-signal of the same echo time of at least two flip angles of acquisition, and it is quantitative can to obtain T1
Figure.Echo-signal using at least two echo times of the same flip angle of acquisition is combined two-by-two, can be gotIt is quantitative
Figure.It is gettingAfter quantitative figure and T1 quantify figure, can according at least two echo-signals of acquisition and this getQuantitative figure and T1 quantitatively scheme, and obtain and eliminateEffect and T1 effect water fat separation figure, finally utilizing can the eliminationEffect
Figure, which is detached, with T1 effect water fat gets accurately Fat quantification information.Therefore, magnetic resonance provided by the embodiments of the present application is joined more
Number quantitative imaging methods can utilize multi-parameter information, while obtain water fat separate picture,Quantitative figure and T1 quantitatively scheme, and
Water fat separate picture can be eliminatedEffect and T1 effects, so as to provide accurately Fat quantification information.
Water fat disjunctive model is described below.
Do not consideringWhen the influence of effect and T1 effects, water fat separation naive model can as shown in formula (4),
In formula (4),
S (t) is collected echo-signal；
W is water signal；
F is fat signal；
For the phase difference between water fat；
The phase that Φ is shared between water fat；
T is the echo time.
In view ofWhen the influence of effect, water fat disjunctive model shown in above-mentioned formula (4) can be extended to formula (5)：
In formula (5),
W is water signal；
F is fat signal；
Δ f is the difference on the frequency of water signal and fat signal；
Φ is the shared phase of water signal and fat signal；
WithRespectively water and fat
T is the echo time.
If on the basis of formula (5), T1 effects are continued with, then water fat disjunctive model can be extended to formula (6)
Wherein, θ is flip angle,
WPDAnd FPDThe respectively proton density figure of water and fat；
TR is the repetition time；
T1WAnd T1FThe respectively T1 times of water and fat；
WithRespectively water and fat
T is the echo time；
Δ f is the difference on the frequency of water signal and fat signal；
Φ is the shared phase of water signal and fat signal.
In the water fat disjunctive model shown in formula (6), because T1 the and T2 comparison in difference of water and fat itself is small, because
This, the difference of the T1 times between water fat can be ignored.AndNot detached by water fat with T1 is influenced, and therefore, is being counted
It calculatesWhen with T1, the difference of the T1 times between water fat can not be considered, thus, above-mentioned formula (6) can be reduced to formula (7)：
In formula (7),
PD is proton density figure；
θ is flip angle,
TR is the repetition time,
TE is the echo time.
In the embodiment of the present application, with multiple echo-signals of more echo sequences of gatherer process acquisition, flip angle
Identical, i.e., θ is identical, and TR is also identical, first do not consider T1, if will with the collected any two echo-signal of a gatherer process into
Row is divided by, so that it may with the complicated item in the formula that disappears (7)Then, then to the two of equal sign
While logarithm is taken, in this way, can obtainCalculation formula show at this as an example, natural logrithm can be taken to the both sides of equal sign
Under example,It can be as shown in formula (8).
Wherein,Calculation formula it is as follows：
Wherein, SmjFor the echo-signal of the jth echo time of m flip angles；
SmiFor the echo-signal of the i-th echo time of m flip angles；
TEjFor SmjEcho time；
TEiFor SmiEcho time；
Wherein, i, j, m are positive integer.
In addition, in formula (7), because TR is it is known that enableAnd enable the both sides of formula (7) simultaneously
Divided by sin θ, formula (7) can be converted into formula (9)：
In the embodiment of the present application, the echo time of the collected echo-signal of same acquisition position of different acquisition process
TE is identical, when TE is identical, the echo-signal of the same acquisition position of different acquisition processPhase
Together, therefore, arbitrary same collected two echo-signal of acquisition position in any two gatherer process can be subtracted each other, you can
Obtain following formula (10)
Wherein, SqmFor the echo-signal of the m echo times of q flip angles；
SkmFor the echo-signal of the m echo times of kth flip angle；
θqFor q flip angles；
θkFor kth flip angle；
TR is the repetition time；
Wherein, q, m, k are positive integer.
In formula (10), flip angle θq, θkAnd collected signal SqmAnd SkmIt is it is known that therefore, passing through formula
(10) R1 can be calculated, after learning R1, T1 can be calculated according to the relationship of R1 and T1.Therefore, according to formula
(10) T1 can be calculated quantitatively to scheme.
Therefore, it can be calculated by above-mentioned formula (8) and (10)And T1, when being calculatedIt, can after T1
With being calculatedIt is updated to and considers with T1In water fat disjunctive model, that is, formula (6) of effect and T1 effects, root
W can be calculated according to formula (6)PDAnd FPD, and WPDAnd FPDIt eliminatesWith the influence of T1 effects.
Then according to the W being calculatedPDAnd FPDIt can carry out Fat quantification.Due to WPDAnd FPDIt eliminatesWith T1 effects
Influence, therefore, the Fat quantification information being calculated will not be becauseInfluence with T1 effects and occur in different sequences
Variation.Thus obtained Fat quantification information has larger diagnostic value.
Based on described above, the embodiment of the present application provides a kind of specific implementation of magnetic resonance multi-parameter quantitative imaging method
Mode.The specific implementation mode of the application is described in detail below in conjunction with the accompanying drawings.
Referring to Fig. 5, magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application includes the following steps：
S51：The echo-signal of the more echo gradient sequences of multi collect, the flip angle acquired every time is different, and acquisition is more every time
The echo-signal of a echo time, and different acquisition process acquisition multiple echo times correspond to respectively it is identical.
S52：The echo-signal of at least two echo times of the same flip angle of acquisition is combined two-by-two, is obtainedIt is quantitative
Figure.
S53：The echo-signal of the same echo time of at least two flip angles of acquisition is combined two-by-two, it is quantitative to obtain T1
Figure.
S54：According at least two echo-signals of acquisition and getQuantitative figure and T1 quantitatively scheme, and obtain water fat
Separation figure.
It is to be appreciated that in the embodiment of the present application, do not limit S52 and S53 executes sequence, in this way, can first carry out
S52, then S53 is executed, S53 can also be first carried out, then execute S52, S52 and S53 can also be performed simultaneously.
Magnetic resonance multi-parameter quantitative imaging method described above can utilize the same flip angle at least two of acquisition to return
The echo-signal of wave time is combined two-by-two, can be gotQuantitative figure, utilizes the same echo of at least two flip angles of acquisition
The echo-signal of time is combined two-by-two, can be obtained T1 and quantitatively be schemed.It is gettingIt, can basis after quantitative figure and T1 quantify figure
At least two echo-signals of acquisition and this getQuantitative figure and T1 quantitatively scheme, and obtain and eliminateEffect and T1 effects
Water fat separation figure.Utilize the eliminationAccurately Fat quantification may be implemented in effect and T1 effect water fat separation figures.
The specific implementation of each step is described below in detail.
It, can be with as shown in Figure 1, be provided with multiple acquisition windows in a TR in S51, multiple acquisitions in a TR
The window corresponding echo time uses TE respectively1、TE2…TENIt indicates.Each the position of multiple acquisition windows in TR corresponds to identical,
In this way, in each TR the echo time of collected multiple echo-signals correspond to it is identical.
In the embodiment of the present application, the echo-signal in multiple acquisition windows in a TR is acquired every time.Acquisition every time
The acquisition parameter of more echo gradient echo sequences is other than flip angle is different, other acquisition parameter all sames, other acquisition parameters
Including but not limited to following parameter：Repetition time TR and corresponding echo time TE.
As an example, the 1st corresponding flip angle of gatherer process (Flip Angle, FA) is θ1, collected each time
The wave signal corresponding echo time is respectively to use TE11、TE12…TE1NIt indicates.Each magnetic resonance gradient collected for the first time returns
Wave can use S11、S12…S1NIt indicates.
The corresponding flip angle FA of 2nd gatherer process is θ2, the collected each echo-signal corresponding echo time point
TE Wei not used21、TE22…TE2NIt indicates.2nd time collected each magnetic resonance gradient echo can use S21、S22…S2NIt indicates.
The corresponding flip angle FA of n-th gatherer process is θn, the collected each echo-signal corresponding echo time point
TE Wei not usedn1、TEn2…TEnNIt indicates.The collected each magnetic resonance gradient echo of n-th can use Sn1、Sn2…SnNIt indicates.
Wherein, θ1≠θ1≠...,≠θn, TE11=TE21... ,=TEn1=TE1, TE12=TE22... ,=TEn2=
TE2... ..., TE1N=TE2N... ,=TEnN=TEN；N, N is positive integer.
The echo-signal so collected by S51 is as shown in table 1.
Table 1
| FA/TE | TE1 | TE2 | … | TEN |
| θ1 | S11 | S12 | … | S1N |
| θ2 | S21 | S22 | … | S2N |
| … | … | … | … | … |
| θn | Sn1 | Sn2 | … | SnN |
Shown in formula (8)Calculation formula can be based on same flip angle as a specific example of S52
Two echo-signals obtainIn this way, S52 can specifically include following steps：
S52a1：The echo-signal of two echo times of the same flip angle of acquisition is combined two-by-two, constitutes one group of signal
Joint group.
S52a2：By corresponding time of the natural logrithm of two echo-signal ratios in combined signal group and two echo-signal
The difference of wave time is divided by, and obtained result isQuantitative figure.
For example, flip angle can be θ by S52a11Two echo-signal S11And S12Joint constitutes one group of combined signal
Group, then S52a2 can be calculated according to following formula (11)Quantitative figure.
Further, because therefore the multiple echo-signals that in signal acquisition process, can obtain same flip angle are
It improvesThe signal-to-noise ratio of image can make full use of collected each echo-signal, respectively by each flip angle of acquisition
The echo-signals of all echo times combine two-by-two, constitute multigroup combined signal group, utilize two in multigroup combined signal group
Echo-signal is obtained based on formula (8)Quantitative figure.
Each group combined signal group can be solved as another specific example of S52 based on thisPass through adduction
Average mode is realized.In this way, S52 can specifically include following steps：
S52b1：The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, is constituted multigroup
Combined signal group.
Specifically, the flip angle of acquisition is θ by this step1N number of echo-signal S11To S1NCombine two-by-two, constitutes multigroup letter
Number joint group, multigroup combined signal group are respectively：{S11,S12, { S11,S13... ... { S1(N-1),S1N}。
It is θ by the flip angle of acquisition2N number of echo-signal S21To S2NCombine two-by-two, constitutes multigroup combined signal group, this is more
Organizing combined signal group is respectively：{S21,S22, { S21,S23... ... { S2(N-1),S2N}。
The rest may be inferred, until the flip angle that will be acquired is θnN number of echo-signal Sn1To SnNCombine two-by-two, constitutes multigroup letter
Number joint group, multigroup combined signal group are respectively：{Sn1,Sn2, { Sn1,Sn3... ... { Sn(N-1),SnN}。
S52b2：Respectively by the natural logrithm of two echo-signal ratios in every group of combined signal group and two echo-signal
The difference of corresponding echo time is divided by, and obtained result is each transitionQuantitative figure.
This step can be specially：By in the above-mentioned each combined signal group constructed two echo-signals and this twice
The wave signal corresponding echo time is updated in formula (8), calculates separately out each transitionQuantitative figure.
Assuming that the echo-signal of two echo times of two flip angles of acquisition, then 4 echo-signals obtained are respectively
S11、S12、S21And S22, under the assumed condition, this step can respectively obtain two transition especially by formula (11) and (12)
Quantitative figureWith
S52b3：Each transition to being calculatedQuantitative figure sums up averagely, and obtained average result is finalQuantitative figure.
In order to improveThe signal-to-noise ratio of quantitative figure, this example pass through to each transitionQuantitative figure sums up averagely, obtains
The average result arrived is as finalQuantitative figure.
Still illustrate by taking above-mentioned assumed condition as an example, this step can be specially：
In addition, because multiple solutions can be constructed by multigroup combined signal groupEquation, in this way, the equation constructed
Number be more than unknown numberNumber, therefore, as the another specific example of the application, in order to further increaseNoise
Than that can solve non trivial solution by least square method, finally obtainIn this way, S52 can also specifically include following step
Suddenly：
S52c1：The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, is constituted multigroup
Combined signal group.
The specific implementation of this step is identical as the specific implementation of S52b1, for the sake of brevity, herein no longer in detail
Thin description.
S52c2：By in every group of combined signal group two echo-signals and two echo-signal corresponding echo time point
It is not updated toCalculation formula in, solved by least square methodQuantitative figure.
It is to be appreciated that described hereinCalculation formula be formula (8) shown inCalculation formula.
The specific implementation of S53 is described below.
It, can be based on two flip angles as a specific example of S53 based on T1 calculation formula shown in formula (10)
The echo-signal of same echo time obtains T1, in this way, S53 can specifically include following steps：
S53a1：The echo-signal of the same echo time of two flip angles of acquisition is combined two-by-two, constitutes one group of signal
Joint group.
As an example, flip angle can be θ by this step1And θ2Echo time be TE1Two echo-signal S11And S21
Joint constitutes one group of combined signal group { S11,S21}。
S53a2：According to the difference of the ratio of the sine value of the corresponding flip angle of two echo-signals in combined signal group
The functional relation of the difference of the ratio of the tangent value of value and the corresponding flip angle of two echo-signals obtains T1 and quantitatively schemes.
Under above-mentioned example, T1, which can be calculated, according to following formula (14) in S53a2 quantitatively schemes.
Further, because of the echo-signal for multiple echo times that the signal that is acquired in S51 is multiple flip angles, because
This can make full use of collected each echo-signal, respectively turn over all of acquisition to improve the signal-to-noise ratio of T1 images
All echo-signals of the same echo time of corner are combined two-by-two, constitute multigroup combined signal group；Utilize multigroup combined signal
Two echo-signals in group are quantitatively schemed based on formula (10) to obtain T1.
Based on this, as another specific example of S53, the T1 that can solve each group combined signal group passes through adduction
Average mode is realized.In this way, S53 can specifically include following steps：
S53b1：All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, are constituted multigroup
Combined signal group.
Specifically, the echo time of n flip angle of acquisition can be TE by this step1All echo-signals join two-by-two
It closes, constitutes multigroup combined signal group.Multigroup combined signal group can be expressed as：{S11,S21, { S11,S31... ...
{S(n-1)1,Sn1}。
It is TE by the echo time of n flip angle of acquisition2All echo-signals combine two-by-two, constitute multigroup signal connection
It is combined.Multigroup combined signal group can be expressed as：{S12,S22, { S12,S32... ... { S(n-1)2,Sn2}。
The rest may be inferred, until being TE by the echo time at all rollovers angleNAll echo-signals combine two-by-two, constitute it is more
Group combined signal group.Multigroup combined signal group can be expressed as：{S1N,S2N, { S1N,S3N... ... { S(n-1)N,SnN}。
S53b2：Respectively according to the sine value of the corresponding flip angle of two echo-signals in every group of combined signal group
The functional relation of the difference of the ratio of the tangent value of the difference of ratio and the corresponding flip angle of two echo-signals obtains every
A transition T1 quantitatively schemes.
This step can be specially：By in the above-mentioned each combined signal group constructed two echo-signals and this twice
The wave signal corresponding echo time is updated in formula (11), calculates separately out each transition T1 and quantitatively schemes.
Assuming that the echo-signal of two echo times of two flip angles of acquisition, then 4 echo-signals obtained are respectively
S11、S12、S21And S22, under the assumed condition, this step can respectively obtain two especially by following formula (14) and (15)
Transition T1 quantitatively schemes T11 and T12.
S53b3：Figure is quantified to each transition T1 being calculated to sum up averagely, obtained average result is final
T1 quantitatively schemes.
In order to improve the signal-to-noise ratio that T1 quantifies figure, this example is summed up averagely by quantifying figure to each transition T1, is obtained
To average result quantitatively scheme as final T1.
Still illustrate by taking above-mentioned assumed condition as an example, this step can be specially：
T1=(T11+T12)/2 (16)
In addition, because multiple equations for solving T1 can be constructed by multigroup combined signal group, in this way, the equation constructed
Number be more than unknown number (T1) number, therefore, as the another specific example of the application, in order to further increase the letter of T1
It makes an uproar and compares, non trivial solution can be solved by least square method, finally obtain T1.In this way, S53 can also specifically include following step
Suddenly：
S53c1：All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, are constituted multigroup
Combined signal group.
The specific implementation of this step is identical as the specific implementation of S53b1, for the sake of brevity, herein no longer in detail
Thin description.
S53c2：By two echo-signals and the corresponding flip angle difference of two echo-signal in every group of combined signal group
It is updated in the calculation formula of T1, solving T1 by least square method quantitatively schemes；
It is to be appreciated that the calculation formula of T1 described herein is the calculation formula of T1 shown in formula (10).
The specific implementation of S54 is described below in detail.
In S54, by collected any two echo-signal in S51 and above-mentioned it can acquireQuantitative figure and
T1 quantitatively schemes to be brought into respectively in formula (6), and generation unknown number is WPDAnd FPDEquation group, by solve equation group solution,
Water signal figure W can be gotPDWith fat signal figure FPD, to get water fat separation figure.
For example, S54 by collected S11 and S12 and can be gotQuantitative figure and T1 quantitatively scheme to distinguish
It is updated in formula (6), so forms following equation group (17)
In equation group, only WPDAnd FPDIt therefore can solve to obtain W by equation group for unknown numberPDAnd FPD。
Further, because multiple echo-signals of multiple flip angles in signal acquisition process, can be collected, it is set with n
A flip angle, each flip angle correspond to the echo-signal of N number of echo time, and n*N echo-signal is so obtained, the n*N
Echo-signal can constitute multiple combined signal groups with combination of two, then by the signal and correspondence in every group of combined signal group
Parameter be updated in formula (6), can obtain multiple unknown numbers be WPDAnd FPDThen equation group is asked by least square method
The solution of solving equations finally obtains water fat separation figure.In this way, the signal-to-noise ratio of water fat separation figure can be improved.
In addition, another example as S54, can also will constitute multiple signals by the n*N echo-signal combination of two
Joint group, then by every group of combined signal group signal and corresponding parameter be updated in formula (6), can obtain multiple
Unknown number is WPDAnd FPDThen equation group solves each solution of equations W respectivelyPDAnd FPD, finally will solve obtain it is multiple
WPDAdduction is average, and obtained average result is as the water signal figure W finally gotPD.Multiple F that solution is obtainedPDAdduction is flat
, the average result obtained is as the water signal figure F finally gotPD。
In addition, as another realization method, Fat quantification information can also include following step after S54 in order to obtain
Suddenly：
Fat quantification information is obtained according to the water fat separation figure got.
This step can be specially：The water signal figure W that S54 is gotPDWith fat signal figure FPDIt is updated to formula (1)
In, to obtain accurate fat ratio.Shown in specific formula such as formula (18).
Because of WPDAnd FPDThe respectively proton density figure of the proton density figure of water and fat, and proton density figure is not scanned
The influence of sequence, because without byThe influence of effect and T1 effects, therefore, obtained fat ratio eliminateEffect and T1 effects
Therefore the influence answered can obtain accurately Fat quantification information by this method.
It is the specific implementation realization method of magnetic resonance multi-parameter quantitative imaging method provided by the embodiments of the present application above.
In the specific implementation, it can provide simultaneouslyQuantitative figure, T1 quantitatively scheme, eliminateEffect and the separation of T1 effect water fat
Figure.
In addition, collected all echo-signals are made full use of, it can by way of summing it up average or least square method
To improve the signal-to-noise ratio of image and improve the precision of Fat quantification.
Moreover, when this method is applied to abdomen imaging, a variety of diagnostic messages can be provided simultaneously, by fixed to fat
Amount,The deposition of iron information etc. that quantitative figure provides can be applied to the classification and precisely diagnosis of hepatic sclerosis.
In order to enable the effect of the application is more prominent, it is fixed that the embodiment of the present application also provides the T1 obtained by this method
Spirogram,Quantitative figure, water signal figure and fat signal figure, respectively as shown in Fig. 6 A to 6D.
As can be seen from these figures, can to obtain signal-to-noise ratio by method provided by the embodiments of the present application higher quantitative
Figure.Therefore, multiple quantitative figures that this method obtains can help clinician to make more accurately to diagnose.
The magnetic resonance multi-parameter quantitative imaging method of above-described embodiment can be as shown in Figure 7 control device execute.Fig. 7 institutes
The control device shown includes processor (processor) 710, and communication interface (Communications Interface) 520 is deposited
Reservoir (memory) 730, bus 740.Processor 710, communication interface 720, memory 730 are completed each other by bus 740
Communication.
Wherein, the logical order of magnetic resonance multi-parameter quantitative imaging can be stored in memory 730, the memory is for example
Can be nonvolatile memory (non-volatile memory).Processor 710, which can call, to be executed in memory 730
The logical order of magnetic resonance multi-parameter quantitative imaging, to execute above-mentioned magnetic resonance multi-parameter quantitative imaging method.As implementation
Example, the logical order of the magnetic resonance multi-parameter quantitative imaging can the corresponding program of software in order to control, execute this in processor and refer to
When enabling, control device can accordingly show the corresponding function interface of the instruction on display interface.
If the function of the logical order of magnetic resonance multi-parameter quantitative imaging is realized in the form of SFU software functional unit and makees
It is independent product sale or in use, can be stored in a computer read/write memory medium.Based on this understanding,
Substantially the part of the part that contributes to existing technology or the technical solution can be in other words for the technical solution of the disclosure
It is expressed in the form of software products, which is stored in a storage medium, including some instructions are used
So that a computer equipment (can be personal computer, server or the network equipment etc.) executes each reality of the present invention
Apply all or part of step of a method.And storage medium above-mentioned includes：USB flash disk, mobile hard disk, read-only memory (ROM,
Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disc or CD etc. it is various
The medium of program code can be stored.
The logical order of above-mentioned magnetic resonance multi-parameter quantitative imaging is properly termed as " magnetic resonance multi-parameter quantitative imaging dress
Set ", which can be divided into each function module.Referring specifically to following embodiment.
The specific implementation mode of magnetic resonance multi-parameter quantitative imaging device provided by the embodiments of the present application is described below.
Referring to Fig. 8, magnetic resonance multi-parameter quantitative imaging device provided by the embodiments of the present application includes：
Collecting unit 81 is used for the echo-signal of the more echo gradient sequences of multi collect, and the flip angle acquired every time is different,
Acquire the echo-signal of multiple echo times every time, and multiple echo times of different acquisition process acquisition correspond to respectively it is identical；
Quantitative figure acquiring unit 82, the echo-signal of at least two echo times of the same flip angle for that will acquire
Combine two-by-two, obtainsQuantitative figure；
T1 quantifies figure acquiring unit 83, the echo-signal of the same echo time of at least two flip angles for that will acquire
Combine two-by-two, obtains T1 and quantitatively scheme；
Water fat detaches figure acquiring unit 84, for according at least two echo-signals of acquisition and gettingIt is quantitative
Figure and T1 quantitatively scheme, and obtain water fat separation figure.
As the specific embodiment of the application,Quantitative figure acquiring unit 82 can specifically include：
First joint subelement 821, the echo-signal of two echo times of the same flip angle for that will acquire is two-by-two
Joint constitutes one group of combined signal group；
First computation subunit 822, for by the natural logrithm of two echo-signal ratios in the combined signal group with
The difference of the two echo-signals corresponding echo time is divided by, and obtained result isQuantitative figure.
As another specific example of the application, T1 quantifies figure acquiring unit 83 and can specifically include：
Second joint subelement 831, the echo-signal of the same echo time of two flip angles for that will acquire is two-by-two
Joint constitutes one group of combined signal group；
Second computation subunit 833, for according to the corresponding overturning of two echo-signals in the combined signal group
The letter of the difference of the ratio of the tangent value of the difference of the ratio of the sine value at angle and the corresponding flip angle of two echo-signals
Number relationship obtains T1 and quantitatively schemes.
As the another specific example of the application, water fat separation figure acquiring unit 84 can specifically include：
By collected all echo-signals and getQuantitative figure and T1 quantitatively scheme to be updated to water fat point respectively
Proton density figure from the proton density figure and fat in model, solving water by least square method, to obtain water fat point
From figure；
Wherein, the water fat disjunctive model is to considerThe water fat disjunctive model of effect and T1 effects.
It is the introduction to magnetic resonance multi-parameter quantitative imaging device provided by the embodiments of the present application, specific implementation above
The description in embodiment of the method illustrated above is may refer to, the effect reached is consistent with above method embodiment, here no longer
It repeats.
The above is only the preferred embodiment of the application, it is noted that for the ordinary skill people of the art
For member, under the premise of not departing from the application principle, it can also make several improvements and retouch, these improvements and modifications are also answered
It is considered as the protection domain of the application.
Claims (14)
1. a kind of magnetic resonance multi-parameter quantitative imaging method, which is characterized in that including：
The echo-signal of the more echo gradient sequences of multi collect, the flip angle acquired every time is different, when acquiring multiple echoes every time
Between echo-signal, and different acquisition process acquisition multiple echo times correspond to respectively it is identical；
The echo-signal of at least two echo times of the same flip angle of acquisition is combined two-by-two, is obtainedQuantitative figure；
The echo-signal of the same echo time of at least two flip angles of acquisition is combined two-by-two, T1 is obtained and quantitatively schemes；
According at least two echo-signals of acquisition and getQuantitative figure and T1 quantitatively scheme, and obtain water fat separation figure.
2. according to the method described in claim 1, it is characterized in that, at least two echoes of the same flip angle by acquisition
The echo-signal of time is combined two-by-two, is obtainedQuantitative figure, specifically includes：
The echo-signal of two echo times of the same flip angle of acquisition is combined two-by-two, constitutes one group of combined signal group；
By the natural logrithm of two echo-signal ratios in the combined signal group echo time corresponding with two echo-signal
Difference be divided by, obtained result isQuantitative figure.
3. according to the method described in claim 1, it is characterized in that, at least two echoes of the same flip angle by acquisition
The echo-signal of time is combined two-by-two, is obtainedQuantitative figure, specifically includes：
The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, constitutes multigroup combined signal
Group；
Respectively by the natural logrithm of two echo-signal ratios in every group of combined signal group echo corresponding with two echo-signal
The difference of time is divided by, and obtained result is each transitionQuantitative figure；
Each transition to being calculatedQuantitative figure sums up averagely, and obtained average result is finalQuantitative figure.
4. according to the method described in claim 1, it is characterized in that, at least two echoes of the same flip angle by acquisition
The echo-signal of time is combined two-by-two, is obtainedQuantitative figure, specifically includes：
The echo-signal of all echo times of each flip angle of acquisition is combined two-by-two respectively, constitutes multigroup combined signal
Group；
By in every group of combined signal group two echo-signals and the two echo-signals corresponding echo time be updated to respectively
Calculation formula in, solved by least square methodQuantitative figure；
Wherein,Calculation formula it is as follows：
Wherein, SmjFor the echo-signal of the jth echo time of the n-th flip angle；
SmiFor the echo-signal of the i-th echo time of the n-th flip angle；
TEiFor SmiEcho time；
TEjFor SmjEcho time；
Wherein, i, j, m are positive integer.
5. according to the method described in claim 1, it is characterized in that, the same echo of at least two flip angles by acquisition
The echo-signal of time is combined two-by-two, is obtained T1 and is quantitatively schemed, specifically includes：
The echo-signal of the same echo time of two flip angles of acquisition is combined two-by-two, constitutes one group of combined signal group；
According to the difference of the ratio of the sine value of the corresponding flip angle of two echo-signals in the combined signal group and
The functional relation of the difference of the ratio of the tangent value of the corresponding flip angle of two echo-signals obtains T1 and quantitatively schemes.
6. according to the method described in claim 1, it is characterized in that, the same echo of at least two flip angles by acquisition
The echo-signal of time is combined two-by-two, is obtained T1 and is quantitatively schemed, specifically includes：
All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, constitute multigroup combined signal
Group；
Respectively according to the difference of the ratio of the sine value of the corresponding flip angle of two echo-signals in every group of combined signal group
And two the corresponding flip angle of echo-signal tangent value ratio difference functional relation, it is fixed to obtain each transition T1
Spirogram；
Figure is quantified to each transition T1 being calculated to sum up averagely, obtained average result is that final T1 quantitatively schemes.
7. according to the method described in claim 1, it is characterized in that, the same echo of at least two flip angles by acquisition
The echo-signal of time is combined two-by-two, is obtained T1 and is quantitatively schemed, specifically includes：
All echo-signals of the same echo time at all rollovers angle of acquisition are combined two-by-two, constitute multigroup combined signal
Group；
By in every group of combined signal group two echo-signals and the corresponding flip angle of two echo-signals be updated to T1's respectively
In calculation formula, T1 is solved by least square method and is quantitatively schemed；
Wherein, the calculation formula of T1 is as follows：
Wherein, SqmFor the echo-signal of the m echo times of q flip angles；
SkmFor the echo-signal of the m echo times of kth flip angle；
θqFor q flip angles；
θkFor kth flip angle；
TR is the repetition time；
Wherein, q, m, k are positive integer.
8. according to the method described in claim 1, it is characterized in that, at least two echo-signals according to acquisition and obtaining
It getsQuantitative figure and T1 quantitatively scheme, and obtain water fat separation figure, specifically include：
By collected all echo-signals and getQuantitative figure and T1 quantitatively scheme to be updated to water fat splitting die respectively
In type, the proton density figure of water and the proton density figure of fat are solved by least square method, to obtain water fat separation figure；
Wherein, the water fat disjunctive model is to considerThe water fat disjunctive model of effect and T1 effects.
9. according to the method described in claim 8, it is characterized in that, the water fat disjunctive model is specific as follows：
Wherein, θ is flip angle,
WPDAnd FPDThe respectively proton density figure of water and fat；
TR is the repetition time；
T1WAnd T1FThe respectively T1 times of water and fat；
WithRespectively water and fatThe inverse of time；
T is the echo time；
Δ f is the difference on the frequency of water signal and fat signal；
Φ is the shared phase of water signal and fat signal.
10. according to claim 1-9 any one of them methods, which is characterized in that at least two echoes according to acquisition
It signal and getsQuantitative figure and T1 quantitatively scheme, and after obtaining water fat separation figure, further include：
Fat quantification information is calculated according to the water fat separation figure got.
11. a kind of magnetic resonance multi-parameter quantitative imaging device, which is characterized in that including：
Collecting unit is used for the echo-signal of the more echo gradient sequences of multi collect, and the flip angle acquired every time is different, adopts every time
Collect the echo-signal of multiple echo times, and multiple echo times of different acquisition process acquisition correspond to respectively it is identical；
Quantitative figure acquiring unit, for joining the echo-signal of at least two echo times of the same flip angle of acquisition two-by-two
It closes, obtainsQuantitative figure；
T1 quantifies figure acquiring unit, for joining the echo-signal of the same echo time of at least two flip angles of acquisition two-by-two
It closes, obtains T1 and quantitatively scheme；
Water fat detaches figure acquiring unit, for according at least two echo-signals of acquisition and gettingQuantitative figure and T1
Quantitative figure obtains water fat separation figure.
12. according to the devices described in claim 11, which is characterized in that describedQuantitative figure acquiring unit specifically includes：
First joint subelement, for the echo-signal of two echo times of the same flip angle of acquisition to be combined two-by-two, structure
At one group of combined signal group；
First computation subunit is used for the natural logrithm of two echo-signal ratios in the combined signal group and two echo
The difference of signal corresponding echo time is divided by, and obtained result isQuantitative figure.
13. according to the devices described in claim 11, which is characterized in that the T1 quantifies figure acquiring unit and specifically includes：
Second joint subelement, for the echo-signal of the same echo time of two flip angles of acquisition to be combined two-by-two, structure
At one group of combined signal group；
Second computation subunit, for the sine according to the corresponding flip angle of two echo-signals in the combined signal group
The functional relation of the difference of the ratio of the tangent value of the difference of the ratio of value and the corresponding flip angle of two echo-signals, is obtained
T1 is taken quantitatively to scheme.
14. according to the devices described in claim 11, which is characterized in that the water fat separation figure acquiring unit specifically includes：
By collected all echo-signals and getQuantitative figure and T1 quantitatively scheme to be updated to water fat splitting die respectively
In type, the proton density figure of water and the proton density figure of fat are solved by least square method, to obtain water fat separation figure；
Wherein, the water fat disjunctive model is to considerThe water fat disjunctive model of effect and T1 effects.
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